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Function pattern to support listed and non-listed arguments [duplicate]

I often want to write functions that take as an argument either a) a rule or b) a list of rules. As an example, when using Replace with just one rule, it does not ...
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I want to write a function which takes multiple arguments varying from 1 to n, where each argument is a triplet. sublistProduct[{$a_1,b_1,c_1$},{$a_2,b_2,c_2$},...] = { $\Pi_{i=1}^{i=n}a_i ,\Pi_{i=1}... 19answers 145k views Where can I find examples of good Mathematica programming practice? I consider myself a pretty good Mathematica programmer, but I'm always looking out for ways to either improve my way of doing things in Mathematica, or to see if there's something nifty that I haven't ... 9answers 4k views How to select minimal subsets? I am a newbie, so please point me in the right direction if you feel this question has been answered somewhere else before. Here goes: Suppose I have a list like this: ... 4answers 4k views Can a function be made to accept a variable amount of inputs? I have a function that takes two inputs and processes them for a single output. What I need is one that can take a varying number of inputs. and process them to a single output. Is this possible in ... 3answers 2k views How is pattern specificity decided? Mathematica has a notion of pattern specificity, which is a partial ordering on patterns. The rules (e.g. DownValues, SubValues,... 4answers 835 views How to Thread with custom functions? Thread vs Map? This function finds n given the nth prime: findPrime[n_] := If[PrimeQ[n], i = 1; While[Prime[i] < n, i = i + 1]; i, False]; This works: ... 2answers 574 views f[arg1, arg2,...,argN] vs. f[{arg1, arg2,...,argN}] I am trying to reproduce the API of a function (written in R) that accepts an arbitrary number of arguments and handles it the same way as it would handle a single argument that is a list of different ... 4answers 936 views Composition of mappings not working as expected I have two functions$f,g:\mathbb{R}^2 \to \mathbb{R}^2$and I define a third one$h:\mathbb{R}^2 \to \mathbb{R}^2$as the composition $$h(x,y) = g(f(x,y))$$ I'm trying to get this function into <... 1answer 1k views Safe way to put a pattern on the right hand side of a rule I'm interested in creating a function or rule that generates its own set of rules. For instance, it would take as an input the expression h[m, n] and the indices <... 2answers 198 views make trace of a matrix listable? I have a list of 2 by 2 matrices and I want the list of their traces. I have been using Map[Tr,mylistofmatrices] But I wonder if there is a way to make ... 3answers 267 views Defining functions when there are a lot of parameters Suppose I have two lists of parameters:$\delta=\{\delta1, \delta2, …\}$and$\gamma = \{\gamma1, \gamma2, …\}$. The question is: how can one use$\delta$and$\gamma$(the parameter vectors) within ... 2answers 286 views Generating all permutations of labels in an expression I have some very long and complex expressions which involve a set of$n$variables, and I want to be able to permute the labels of the variables. I will give a simple example, instead of my awful ... 1answer 291 views Replacement rules with Lists first time user and not quite familiar with how to enter my code here properly, but this isn't lengthy.. I have a previously defined function that computes the total time it takes to ride a bike with ... 2answers 64 views About composition of functions (I don't want to use a vector variable function) f2[x_, y_] := x^2 + y^3; g[t_] := {t^2, 3*t+1}$g$returns a list, but$f_2\$ is a two variable function. So, we cannot compose these functions: ...

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